The hydroxyapatites were popularly been used as the ocular implant due to low incidence of post-operative exposure, infections, and excellent motility. For this purpose, it has been known that the drilling and peg implantations are performed after ingrowth of fibrovascularization tissue into the hydroxyapatites, so that ball and socket movement were occur. The authors reviewed 140 patients(140 eyes) who received enucleation or evisceration with the implantation of hydroxypapatite from Dec. 1991 to Jun. 1995. We performed that drilling after confirmation of the fiborvascularized hydroxyapatite by Technetium-99m-MDP bone scan, and investigated the method and complications. Among the 140 eyes(140 Patients), 39 eyes(28%) were found to have complications: 17 cases of peg extraction(44%), 10 cases of peg protrusion(26%), 4 cases of over-growth of granulation tissue(11%), 3 cases of poor motility(7%), 3 cases of hydroxyapatite exposure(7%) and 2 cases of malposition of peg(5%). Redrilling was performed in 20 eyes(51%) and exchanged by the screw peg due to re-extraction of peg in 4 eyes(20%). In a conclusion, overall the frequency of complications after drilling was about 28% and the most frequent complication was peg extraction.
Durapatite* ; Humans ; Hydroxyapatites ; Incidence

The change of conditions of hydroxyapatite synthesis can affect not oniy the material properties, but also the body reaction to the hydroxyapatite implants. To find out conditions for preparing more biocompatible hydroxyapatite implants as bone graft substitute. we evaluated the biologic response to the dense synthetic hydroxyapatite implants, made with various synthetic conditions, placed in corticocancellous defects of rabbits' long bone. The hydroxyapatites were synthesized with coprecipitation technique using Ca(NO3) 4H2O and (NH4)2HPO4, made with various Ca/P ratio and aging temperatures. Four kinds of hydroxyapatites were selected to use as implants(HA I: Ca/P ratio 1.5, aging temperature 90degrees C; HA V :1.5 , 30degrees C; HA VI: 1.83, 30degrees C; and HA lX: 1.67, 30degrees C). These hydroxyapatites were pressed and sintered at l300degrees C to fabricate dense plates. Biomechanical test and rnorphological examination were performed using Instron, light microscope and electron microscope. The characteristics of hydroxyapatite powder and sintered body were more significantly affected by siarting Ca/P ratios. The bonding strength of HA IX(1.67, 30degrees C) with bone was grcatest at 4 or 8 weeks after implantation with statistically significant difference(p<0.05). Bonding behavior betweeb HA IX and bone was most excellent in terms of new bone formation and new bone ingrowth into resorbed surface of hydroxyapatite plate.
Aging ; Durapatite* ; Hydroxyapatites ; Osteogenesis ; Transplants

PURPOSE: The purpose of this study was to histomorphometrically evaluate the osteoconductivity of a new biphasic calcium phosphate ceramics with fully interconnected microporous structure. MATERIAL AND METHODS: Osseous defects created in the rabbit calvaria were filled with four different bone graft substitutes. Experimental sites were filled with a new fully interconnected microporous biphasic calcium phosphate with(BCP-2) or without(BCP-1) internal macropore of 400micrometer in diameter. MBCP(Biomatlante, France) and Bio-Oss(Geistlich Pharma, Switzerland) were used as controls in this study. Histomorphometric evaluation was performed at 4 and 8 weeks after surgery. RESULT: In histologic evaluation, new bone formation and direct bony contact with the graft particles were observed in all four groups. At 4 weeks, BCP-1(15.5%) and BCP-2(15.5%) groups showed greater amount of newly formed mineralized bone area(NB%) compared to BO(11.4%) and MBCP(10.3%) groups. The amounts of NB% at 8 weeks were greater than those of 4 weeks in all four groups, but there was no statistically significant differences in NB% between the groups. CONCLUSION: These results indicate that new bone substitutes, BCP with interconnected microporous structure and with or without internal macroporous structures, have the osteoconductivity comparable to those of commercially available bone substitutes, MBCP and Bio-Oss.
Bone Substitutes ; Calcium ; Ceramics ; Hydroxyapatites ; Minerals ; Osteogenesis ; Skull ; Transplants

STUDY DESIGN: Retrospective study. PURPOSE: To compare the union rate of posterolateral lumbar fusion (PLF) using demineralized bone matrix (DBM) versus hydroxyapatite (HA) as bone graft extender. OVERVIEW OF LITERATURE: To our knowledge, there has been no clinical trial to compare the outcomes of DBM versus HA as a graft material for PLF. METHODS: We analyzed prospectively collected data from consecutive 79 patients who underwent instrumented PLF. Patients who received DBM were assigned to group B (n=38), and patients who received HA were assigned into group C (n=41). The primary study outcome was fusion rate assessed with radiographs. The secondary outcomes included pain intensity using a visual analogue scale, functional outcome using Oswestry disability index score, laboratory tests of inflammatory profiles and infection rate. RESULTS: One year postoperatively, bone fusion was achieved in 73% in group B and 58% in group C without significant difference between the groups (p=0.15). There were no differences between the groups with respect to secondary outcomes. CONCLUSIONS: DBM would provide noninferior outcomes compared to the HA as a fusion material for PLF, and could be a notable alternative.
Bone Matrix* ; Durapatite* ; Humans ; Hydroxyapatites ; Prospective Studies ; Retrospective Studies ; Transplants

PURPOSE: The aim of this study was to evaluate the improvement of osteogenic potential of biphasic calcium phosphate (BCP) bone substitute coated with synthetic cell-binding peptide sequences in a standardized rabbit sinus model. METHODS: Standardized 6-mm diameter defects were created bilaterally on the maxillary sinus of ten male New Zealand white rabbits, receiving BCP bone substitute coated with synthetic cell binding peptide sequences on one side (experimental group) and BCP bone substitute without coating (control group) on the other side. Histologic and histomorphometric analysis of bone formation was carried out after a healing period of 4 or 8 weeks. RESULTS: Histological analysis revealed signs of new bone formation in both experimental groups (4- and 8-week healing groups) with a statistically significant increase in bone formation in the 4-week healing group compared to the control group. However, no statistically significant difference in bone formation was found between the 8-week healing group and the control group. CONCLUSIONS: This study found that BCP bone substitute coated with synthetic cell-binding peptide sequences enhanced osteoinductive potential in a standardized rabbit sinus model and its effectiveness was greater in the 4-week healing group than in the 8-week healing group.
Artificial Cells ; Bone Regeneration ; Bone Substitutes ; Calcium ; Durapatite ; Humans ; Hydroxyapatites ; Male ; Maxillary Sinus ; Oligopeptides ; Osteogenesis ; Rabbits

PURPOSE: The purpose of this study was to determine the biological effects of cyanoacrylate-combined calcium phosphate (CCP), in particular its potential to act as a physical barrier - functioning like a membrane - in rabbit calvarial defects. METHODS: In each animal, four circular calvarial defects with a diameter of 8 mm were prepared and then filled with either nothing (control group) or one of three different experimental materials. In the experimental conditions, they were filled with CCP alone (CCP group), filled with biphasic calcium phosphate (BCP) and then covered with an absorbable collagen sponge (ACS; BCP/ACS group), or filled with BCP and then covered by CCP (BCP/CCP group). RESULTS: After 4 and 8 weeks of healing, new bone formation appeared to be lower in the CCP group than in the control group, but the difference was not statistically significant. In both the CCP and BCP/CCP groups, inflammatory cells could be seen after 4 and 8 weeks of healing. CONCLUSIONS: Within the limits of this study, CCP exhibited limited osteoconductivity in rabbit calvarial defects and was histologically associated with the presence of inflammatory cells. However, CCP demonstrated its ability to stabilize graft particles and its potential as an effective defect filler in bone augmentation, if the biocompatibility and osteoconductivity of CCP were improved.
Animals ; Bone Regeneration ; Calcium ; Calcium Phosphates ; Collagen ; Cyanoacrylates ; Hydroxyapatites ; Membranes ; Osteogenesis ; Porifera ; Rabbits ; Transplants

PURPOSE: In this study, the effect of micro-macroporous biphasic calcium phosphate(MBCP) incorporated with inorganic polyphosphate for bone regeneration in the calvaria of rabbit was evaluated. MATERIALS AND METHODS: The procedure of guided bone regeneration was performed with titanium reinforced expanded polytetrafluoroethylene(TR-ePTFE) membrane. Four animal groups were compared : 1) TR-ePTFE membrane for negative control group, 2) TR-ePTFE membrane filled with MBCP for positive control group, 3) TR-ePTFE membrane filled with MBCP soaked in 4% inorganic polyphosphate for experimental group I, and 4) TR-ePTFE membrane filled with MBCP soaked in 8% inorganic polyphosphate for experimental group II. RESULTS: 1. Negative control group showed the highest new bone formation at 16 weeks. 2. Positive control group showed the smallest new bone formation compared to other groups. 3. 8% inorganic polyphosphate induced more volume of bone formation, otherwise experimental group II did not show significant difference compared to negative control group. CONCLUSION: These results suggest that inorganic polyphosphate has a promoting effect on bone regeneration, possibly by enhancing osteoconductivity of the carrier and by increasing osteoinductivity of the defected alveolar bone tissue.
Animals ; Bone and Bones ; Bone Regeneration ; Calcium ; Hydroxyapatites ; Membranes ; Osteogenesis ; Skull ; Titanium

PURPOSE: The aim of this study was to evaluated biphasic calcium phosphate applied in surgically created 1-wall periodontal intrabony defects in dogs by histometrical analysis. MATERIAL AND METHOD: Critical sized(4 mm x 4 mm), one wall periodontal intrabony defects were surgically produced at the proximal aspect of mandibular premolars in either right and left jaw quadrants in four canines. The control group was treated with debridement alone, and experimental group was treated with debridement and biphasic calcium phosphate application. The healing processes were histologically and histometrically observed after 8 weeks. RESULTS: In biphasic calcium phosphate group, more new bone and cementum formation, less epithelium and connective tissue attachment were observed compared to other groups. But there was no statistical significance. CONCLUSION: Though the statistically significant difference could not be found, it seemed that there was more new bone and cementum formation with applying biphasic calcium phosphate in 1 wall intrabony defects in dogs by preventing junctional epithelium migration.
Animals ; Bicuspid ; Calcium ; Connective Tissue ; Debridement ; Dental Cementum ; Dogs ; Epithelial Attachment ; Epithelium ; Hydroxyapatites ; Jaw

STUDY DESIGN: Prospective randomized noninferiority trial. PURPOSE: To evaluate whether the union rate of anterior cervical discectomy and fusion (ACDF) using a polyetheretherketone (PEEK) cage filled with a mixture of hydroxyapatite (HA) and demineralized bone matrix (DBM) is inferior to that of a mixture of beta-tricalcium phosphate (beta-TCP) and HA. OVERVIEW OF LITERATURE: There have been no clinical trials investigating the outcomes of a mixture of HA and DBM in a PEEK cage in ACDF. METHODS: Eighty-five eligible patients were randomly assigned to group B (n=43), in which a PEEK cage with a mixture of HA and DBM was used, or group C (n=42), in which a PEEK cage with a mixture of HA and beta-TCP was used. The primary study endpoint was the fusion rate, which was assessed with dynamic radiographs and computed tomography (CT) scans. Secondary endpoints included pain intensity using a visual analogue scale, functional outcome using a neck disability index score, laboratory tests of inflammatory profiles, and the infection rate. RESULTS: Seventy-seven patients (38 in group B and 39 in group C) were included in the final analysis. One year postoperatively, bone fusion was achieved in 87% of group B patients and 87% of group C patients on dynamic radiographs, and 87% of group B patients and 72% of group C patients on CT scans (p=1.00 and 0.16, respectively). There were also no between-groups differences with respect to the secondary endpoints. CONCLUSIONS: A HA/DBM mixture inside a PEEK cage can provide noninferior outcomes compared to a HA/TCP mixture in ACDF.
Bone Matrix* ; Diskectomy* ; Durapatite ; Humans ; Hydroxyapatites ; Neck ; Prospective Studies* ; Tomography, X-Ray Computed

Cytotoxicity and cytocompatibility remains the principal theme for biomaterials application in medicine. The purpose of this study was to investigate the cytotoxicity and cytocompatibility of collagen/hydroxyapatite(CHA) composite material in vitro in order to provide useful scientific basis for clinical use. Cellular cultivation in vitro and MTT assay were conducted for evaluating the composite material's influence on the morphology, growth and proliferation of cultured cell(L-929 cell). The hemolysis test was also performed for evaluating the impact on the function and metabolism of erythrocyte. These results demonstrated that the CHA composite material had no cytotoxicity and no hemolytic effect, and it might not be harmful to the morphology of the L-929 cell. The growth and proliferation of the L-929 cell could not be inhibited significantly. The cytotoxicity score of the composite material was grade 0. The hemolysis rate was 1.85%. In conclusion, collagen/hydroxyapatite (CHA) composite material might have good cytocompatibility and be safe for clinical use.
Animals ; Biocompatible Materials ; toxicity ; Cells, Cultured ; Collagen ; toxicity ; Hydroxyapatites ; toxicity ; Mice ; Prostheses and Implants ; Toxicity Tests ; Trachea